26 THE O:EDOGONIACEA E 
to proceed further with the group concerned. On the other 
hand, of course, no key to plant forms can be so simple as to 
preclude the necessity of having a modicum of intelligence 
regarding scientific terms. Some species are more closely 
related than are others, and one must exercise judgment in the 
evaluation of characteristics. One measurement will not suffice, 
a single oogonium may be a monstrosity, one oospore may be 
parasitized, and a single vegetative cell may be far from typical. 
The keys of the following pages have been constructed in as 
simple a fashion as possible with the particular aim of enabling 
the student of the group to name his collection. 
It is very convenient to use the group name Stephanokonte 
proposed by Blackman and Tansley (1902) as a division of the 
class Chlorophycee and including those forms whose motile 
reproductive cells have a crown of cilia round the clear anterior 
end. Quite recently Fritsch (1927) has elevated the Isokonte 
to be synonymous with and to replace Chlorophycee (1.e., the 
Chlorophycee exclusive of the Heterokonte). Oedogoniales with 
its single family Oedogoniacee is further considered by Fritsch 
as a group division of Isokonte. 
There is no question but that the Oedogoniales have 
characteristics of cell wall, cell division, and reproductive 
structures that separate them as a quite readily distinguishable 
group. Even Fritsch remarks that they are a “‘sharply cir- 
cumscribed group affording but few points of affinity with the 
other Isokonte”’ (loc. cit., p. 212). It appears to the writer to 
be to the best interests of taxonomic nomenclature to retain the 
group name Stephanokonte as a division of the Chlorophycee, 
as noted above. 
There is but one order, OEDOGONIALES. The simple or 
branched filaments are almost invariably attached, at least 
during a part of their life history, except in Oedocladium. 
The single family, OEDOGONIACE, may be characterized as 
follows: 
